10/03/2023
It’s that time of year again. Turn back the irrigation system to avoid fungal disease in your lawn and garden.
Look out for Large Patch...
What is it?
A common fungus that attacks St. Augustine lawns, Large Patch (formerly known as Brown Patch) forms roundish yellow or tan patches, 3-10 feet in diameter, in early October when daytime temps are around 80 degrees and nighttime temps are below 70 degrees. They're even more prevalent in spring.
Why don't I want it?
Beyond aesthetics, Large Patch weakens the overall health of your lawn, making it more susceptible to other diseases, pests, and environmental stressors.
How will I know if I have it?
In the fall, you might see a yellowish ring of grass surrounding the patch as the disease progresses. Sometimes, the center of the patch can recover, creating a "doughnut" appearance. Individual grass blades will have dark-brown to purple spots, will pull easily away from the stems, and will look brown and rotted at the base.
How do I avoid it?
No two ways about it, preventing Large Patch is all about proper lawn management: don't cut grass too short, avoid overirrigating and overfertilizing, and amend with compost and aerate to avoid compacted soil.
I see it. Now what?
While prevention is the key, organic fungicides can help stem an attack: neem oil, sulfur and copper-based fungicides, cornmeal and baking soda can be effective. However, the best place to start if you suspect you have Large Patch is to check with an expert. Contact Texas A&M AgriLife Extension Service (936) 539-7822.
